Consider urbanized area, be it a municipality, district or entire city, which suffers severe crime problems. The area can and have to independently decide how to avert lawbreaking.

Legistaltion issues aside, in this thesis we consider provision of the local safety system. For instance we can imagine that it shall consists of:
\begin{itemize}
\item enhancement and extension of the streetlights
\item monitoring system
\item improvement and proliferation of the police stations
\end{itemize}

Depending on the place where particular citizen lives and how wealthy is, she is differently affected by criminality, e.g. living in well illuminated district adjacent to the police station be more safe than living next to gloomy devastated bouildings. Nevertheless diminishing abomination in the area should be of interest to all citizens regardless whether or not they can afford their own monitoring system and lamps lest living in the separate fortresses without possibility of taking part in everyday city life. Moreover taking part in funding the public system may be cheaper than maintaining the private one.

Local safety system is apparently a public good, for no one from the community can be excluded from the police protection, light or camera sight if provided. The question is how to share costs among citizens efficiently and equitably that everyone agrees to pay her quota and the system is founded. Capability of the safety system itself is not the subject of this thesis.

